Laminated ceramic condensers are known to be condensers which can meet the demands for miniaturization of electronic parts, for high frequency applications, and for higher reliability of electronic parts.
Conventional laminated ceramic condensers are produced by printing a noble metal paste having high temperature stability, e.g., Pt, Pd-Pt, etc., on a thin sheet of a highly dielectric ceramic composition, e.g., barium titanate, etc., to form an electrode, laminating a plurality of the sheets, sintering the laminate, and then providing an outer electrode in such a manner that each electrode of the ceramic layers (condenser elements) may be connected in parallel.
In order to cope with the trend of miniaturization of electronic parts, it is desired to decrease the number of condenser elements to be laminated to as low as a number practically possible. To achieve this, the ceramic composition to be used should have a dielectric constant as high as possible, to thereby provide condenser elements having high capacity.
Further, when a laminated ceramic condenser is manufactured using a conventional ceramic composition, sintering should be conducted at high temperatures above 1300.degree. C. Accordingly, a noble metal paste having excellent stability to high temperatures is required as an electrode material, thus making the product expensive. If sintering could be effected at a low temperature, the electrodes could be formed by using inexpensive electroconductive materials, such as Ni, Co, Fe, etc. It has been strongly desired, therefore, to develop condenser materials that can be sintered at low temperatures below 1100.degree. C.
In the production of electrostriction elements, also, the materials therefor have been increasingly required to have high dielectric constants in order to enhance electrostriction, and to have a capability of being sintered at low temperatures from the same standpoint as in the case of condenser elements.
The benefits of dielectric ceramic compositions having high dielectric constants and low sintering temperatures are not only desirable with respect to the above-described laminated condensers and electrostriction elements, but are also desirable in other fields for analogous reasons.